Try a tree guard zipper

If you use 3” or 4” diameter corrugated plastic tree guards
to protect trees on your nursery from deer and other types of trunk damage,
consider using a tree guard zipper to install and remove the protective
sleeves. You will save time, prevent scarring and scratching of the trunks,
and spare your hands the pain and fatigue that comes with gripping and
spreading the edges of the guard. The zipper is a triangular piece of
cast aluminum with a handle at the narrow end of the triangle and channels
running down the sides. It spreads the edges of the plastic guards for
you, making your job much easier and quicker. (learn
more)